It is known to incorporate various phosphites with polymers as disclosed in U.S. Pat. No. 3,305,520 and phosphites with tetraaryl tin as shown in Canadian Pat. No. 727,700. However, these references deal solely with phosphites such as triaryl and trialkyl phosphites. Due to increased molding temperatures and use temperatures of molded shapes of polycarbonates, it is increasingly more important to prepare polycarbonates having increased stability to thermal degradation or discoloration due to elevated temperatures.
Epoxy compounds have been known to provide stabilization for polycarbonates as disclosed in an application of C. A. Bialous et al. entitled "A Hydrolytically Stable Polycarbonte Composition", Ser. No. 427,832 filed Dec. 26, 1973 now U.S. Pat. No. 3,839,247, issued Oct. 1, 1974 and assigned to the same assignee as the present invention.
However, it has been found that the epoxy compounds prepared from epichlorodydrin described in the C. A. Bialous et al. application normally contain significant amounts of chlorine as an impurity which results in poor molded color of polycarbonate compositions containing these particular epoxy compounds.
These polycarbonate compositions are suitable for producing bottles which are free of the drawbacks of hazing and brittleness of clear polycarbonate bottles when subjected to water or moisture under elevated temperatures.
In the art, there are several patents directed to using epoxies with polycarbonates. One such patent is U.S. Pat. No. 3,489,716, which specifically discloses employing with a polycarbonate a cycloaliphatic epoxy containing 1-2-cycloaliphatic rings. Another patent is U.S. Pat. No. 3,634,312, which discloses the use of a great host of epoxies that can be used with a copolycarbonate and specifically poly(bisphenol-A-carbonate-co-phosphite).